44 replies to this topic

[scott_larry_d]

I will try to plot a course between the twin reefs of “analysis paralysis and sunk cost fallacy”. I’ll take your advice on getting something that works for the moment and improving on anniversaries, at my age every day is an anniversary of something or other

Hey Marcus1! I'm not going to recommend any particular eyepiece for you but will say don't be afraid of the used market. You can try various eyepieces (and/or telescopes, filters, etc.) and if they are disagreeable to you they can be sold for the same amount you paid for them usually. All you'd be out is some shipping expenses to get some hands on experience.

 

Also +1 on a chair. Sitting to observe adds about 25% to the size of any scope! Enjoy the journey.

[The Rigger]

I owned an 8" SCT for 11 years and owned a couple hundred eyepieces during that time.

I do encourage the acquisition of a 2" diagonal so that you can use 2" eyepieces, which will give you wider true fields at low power, since the scope is limited in field size due to its long focal length and internal baffles.

A side question, asking as a new-to-me 8" EdgeHD owner:  I had read somewhere - perhaps even in the Celestron EdgeHD specs & docs? - that while the 9.25" and larger OTAs were fine with 2" visual hardware, for some unspecified reason the eight-incher could only use 1.25" diags and eyepieces.

I take it from your comment above that this is in fact not the case?

 

Also, any thoughts on a decent 45° image erector prism - either 2" or 1.25" - in lieu of a 90° diagonal?

 

TIA,

[Mike W]

And those 82° eyepieces come in a wide swath of focal lengths: 4mm, 7/8mm. 10mm, 13mm, 16/15mm, 21mm, and 28mm

(note: the ones with 2 focal lengths are label focal length/actual focal length).

You're right--incredible values just as long as glasses are not in the picture.

Don, would it be a good idea for him to find out what degree E/P he likes best? For instance I prefer 68-70 but am ok with Radians. Maybe a 30mm UFF to start? I didn't read the whole thread so I could be way off base..............

[Starman1]

Don, would it be a good idea for him to find out what degree E/P he likes best? For instance I prefer 68-70 but am ok with Radians. Maybe a 30mm UFF to start? I didn't read the whole thread so I could be way off base..............

Though expensive, ultimately experimentation is the only way to find out what you really like.

[davidgmd]

A side question, asking as a new-to-me 8" EdgeHD owner:  I had read somewhere - perhaps even in the Celestron EdgeHD specs & docs? - that while the 9.25" and larger OTAs were fine with 2" visual hardware, for some unspecified reason the eight-incher could only use 1.25" diags and eyepieces.

I take it from your comment above that this is in fact not the case?

 

Also, any thoughts on a decent 45° image erector prism - either 2" or 1.25" - in lieu of a 90° diagonal?

 

TIA,

  
The 8” Celestron SCTs don’t have as large a rear cell opening as the 9.25” and up SCTs. The 8” will vignette a little with a 2” diagonal and low power, wide field 2” eyepiece. That doesn’t mean you can’t use a 2” diagonal and 2” eyepieces with them to good effect. The slight peripheral dimming is too subtle for me to see with a 31 mm 82 degree Nagler in my 8” Edge HD.

  

As to 45 degree diagonals, I would consider one only for terrestrial viewing. If I’m looking at celestial objects above 45 degrees, a 90 degree diagonal is far superior ergonomically. And almost a requirement as I approach zenith. Unless you have a rubber neck.

[Starman1]

The 8” Celestron SCTs don’t have as large a rear cell opening as the 9.25” and up SCTs. The 8” will vignette a little with a 2” diagonal and low power, wide field 2” eyepiece. That doesn’t mean you can’t use a 2” diagonal and 2” eyepieces with them to good effect. The slight peripheral dimming is too subtle for me to see with a 31 mm 82 degree Nagler in my 8” Edge HD.

As to 45 degree diagonals, I would consider one only for terrestrial viewing. If I’m looking at celestial objects above 45 degrees, a 90 degree diagonal is far superior ergonomically. And almost a requirement as I approach zenith. Unless you have a rubber neck.

In addition:
--45° diagonals have smaller clear apertures and vignette more than 90° diagonals.
--45° diagonals have slightly lower quality optics than 90° diagonals because they are made pretty much only for low powers.
--45° diagonals are intended for daytime terrestrial use, but SCTs cannot achieve the 20-40x magnifications usable in daylight both because eyepieces that achieve thise powers won't be available and because the secondary shadow will be obtrusive due to the observers' smaller daytime pupils.

So:
--SCTs not usable as terrestrial scopes
--45° diagonals a bad idea except on refractors used for terrestrial viewing.

[Jon Isaacs]

 

--45° diagonals have slightly lower quality optics than 90° diagonals because they are made pretty much only for low powers.

 

In addition, 45° diagonal use Amici type prisms which split the light into two paths and then rejoin them. This causes phase issues between the two paths resulting in lower contrast as well as a spike caused the the line between the two paths.

 

Jon

[Albie]

As others have said, it's very important to have an height adjustable observing chair. Starbound is the most recommended but I like the TeleVue Air Chair for it's pneumatic lift and easy portability. If your scope came with very basic plossls then the Astro-Tech Paradigm/Agena Starguider ED's are a nice bump up in quality and viewing comfort IMO. They are reasonably priced too 

 

https://astronomics....ndor=Astro-Tech.

The Televue Air Chair looks like a drummer's throne . I imagine one could buy a drummer's throne with the lift lever for a lot less . Or the op could have someone help him build a Denver Chair if he's on a budget .

 

I built this Denver Chair 19 years ago , it still works well .

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[Mike W]

The Televue Air Chair looks like a drummer's throne . I imagine one could buy a drummer's throne with the lift lever for a lot less . Or the op could have someone help him build a Denver Chair if he's on a budget .

 

I built this Denver Chair 19 years ago , it still works well .

Wrong again, much heavier build than a drummers throne and will retain it's value like any Televue product.

 

https://www.bing.com...lyLmh0bWw&ntb=1

[Jon Isaacs]

Wrong again, much heavier build than a drummers throne and will retain it's value like any Televue product.

 

https://www.bing.com...lyLmh0bWw&ntb=1

 

I'd like to see a photos of someone with an Air Chair viewing through a TV-102 at both the horizon and the zenith. The way I observe, 8  inches of height adjustment is just not enough for a tripod without an adjustable height center column.. 

 

Jon

[Mike W]

I'd like to see a photos of someone with an Air Chair viewing through a TV-102 at both the horizon and the zenith. The way I observe, 8  inches of height adjustment is just not enough for a tripod without an adjustable height center column.. 

 

Jon

Easy, you move the chair a little to the side and rotate the diagonal to get at the horizon. Are you telling me you never have to move your chair? Are you saying I'm stretching the truth? I don't understand?

Edited by Mike W, 21 April 2025 - 11:29 PM.

[Starman1]

I'd like to see a photos of someone with an Air Chair viewing through a TV-102 at both the horizon and the zenith. The way I observe, 8 inches of height adjustment is just not enough for a tripod without an adjustable height center column..

Jon

I use one with my 4" f/7 refractor. At the horizon, I tip the diagonal sideways to horizontal. My mount has a center pillar that raises the scope.

[TayM57]

How often do you refractor guys use the fracs if you have newtonians?

I have a 8" f/3 reflector which gives very wide views like a refractor does. Though, it's a rare night I have it out, and it's when I want to get wide views of large objects like the Viel, NGC7000, Double cluster, and open clusters that are large and sometimes sparse enough that only a low power and wide field will show it.

The Plaiades is a good example of this. None of my other newtonians show the Plaiades nearly as well as the 8" f/3 can.

Different tools for different jobs,

Sometimes I'll have the 8" out to compliment the main scope of the night for the very low power wide fields.

[Albie]

Wrong again, much heavier build than a drummers throne and will retain it's value like any Televue product.

 

https://www.bing.com...lyLmh0bWw&ntb=1

What do you you mean by wrong again ? You following me ? I can play that game if that's what you want .

Edited by Albie, 22 April 2025 - 08:47 AM.

[Albie]

Wrong again, much heavier build than a drummers throne and will retain it's value like any Televue product.

 

https://www.bing.com...lyLmh0bWw&ntb=1

Not wrong at all . I have had quite a few drum thrones over the years as I was a drummer until carpal tunnel ended it . I agree with Jon that there's not enough movement with drum throne style seats . I prefer the Denver chair . A Catsperch chair would be nice if I could afford it .

 

Here's the only  pic of my last drum throne from my practice kit before I sold it . Not a good picture .

Edited by Albie, 22 April 2025 - 09:07 AM.

[Jon Isaacs]

Easy, you move the chair a little to the side and rotate the diagonal to get at the horizon. Are you telling me you never have to move your chair? Are you saying I'm stretching the truth? I don't understand?

 

I'm saying 8 inches of travel is not enough to for me to view comfortably. I get it that you can rotate the diagonal but that inverts the image and makes star hopping more difficult. I consider that a big and unnecessary compromise.

 

And with a Dob, it's not enough range. 

 

How do the feet work in sand and soft dirt? 

 

Jon

[Mike W]

Wow, how did this topic go so sideways. I can guess.............................

[Dobs O Fun]

Let's stop the bickering and help the originator of the topic. We have a fairly new user and we all should be showing good netiqutte.

 

One tenant to remember is to play nice, stop calling people out.

[TayM57]

I agree with Don. Experimentation is the only way to go, although it can get expensive fast. 

 

I was lucky I started off with access to a full set of Ethos + 24 Pan 15 years ago. That helped me decide what I liked best, which was 100 deg AFOV EPs like the Ethos. 

 

OP didn't state whether he observes with glasses or not, but it sounds this isn't the case. Budget is also not mentioned. So, I would go with a full set of either the Ethos or the XWAs. OP has a slow scope, so the XWAs should work. 

 

Wearing glasses changes the options though. If glasses, then the options are, ordered from decreasing AFOV: 

 

ES92s (92°)
Noblex Docter 12.5mm (85°)

Apollo 11 (85°)

Nagler Type 7's (82°)

Morpheus (76 - 79°)
Delos (72°)
Pentax XWs (70°)
Delites (62°)
 

I've tried all of the above except for the Docter/N7's. Out of the list above, which do I like the best? It depends on what I'm observing. There is no one best EP. I do have an affinity for large wide AFOV, so for me, the ES92's hit that sweet spot. If it is optical fidelity I'm after, than it is the Delos, hands down. Sometimes the focal ratio of the scope + target observing dictates the choice of EP. 

Edited by TayM57, 22 April 2025 - 01:17 PM.

[TayM57]

 

The eyepiece journey. For all of us it begins with a single step. For many, myself included, it never ends. 

 

 

-Victor

 

It did, at one point, end for me. When I got the 9ES120 to compliment my mix of Ethos and ES100° EPs, that was my final set for many years. Then my stig got worse, and my contacts too bothersome at night. Viewing at night with contacts was becoming impossible. 

 

Switching to glasses, has resulted in a journey seemingly without end. I've tried Delos, Delites, Morphii, A11, XWs, all in a chase of that nirvana I had with my 100° EPs. Now, I've come full circle, and I'm building out my ES92's, right where I started- with wide AFOV EPs. I'm pretty sure that my quest ends with the ES92s. I'll still fill out my Morphii, Delos, and Delites but nothing really tops the experience of 100° EPs, which is why I've settled on building out my ES92s.